6-38
System Design
AMD-K5 Processor Technical Reference Manual
18524C/0—Nov1996
6.4.5
Stop Clock State
The processor enters the Stop Clock state when system logic
turns off CLK while STPCLK is asserted. This is the minimum-
power state and it can only be entered from the Stop Grant
state, after BRDY has been returned for the Stop Grant special
bus cycle. In the Stop Clock state, the processor’s phase-lock
loop and I/O buffers are disabled, except for the I/O buffers on
CLK and the JTAG signals. System logic should not change the
state of any signals, and the processor does not recognize any
signal edges in the Stop Clock state.
When CLK is restarted, the processor returns to the Stop Grant
state, responds to inputs in the next clock, but cannot drive bus
cycles until its phase-lock loop is synchronized. The latter
takes several clocks (see the data sheet for this specification).
The CLK can be driven with a different frequency and/or the
bus-to-processor clock ratio can be changed on the BF input(s)
upon restarting CLK.
6.4.6
Clock Control Compatibility with Pentium Processor
The differences in clock control functions between the
AMD-K5 and Pentium processors are described in Section A.5
on page A-12.
6.5
Power and Ground Design
All of the processor input signals operate at 3 V except CLK,
which can operate at 3 V or 5 V. Compatible 3-V chipsets are
available. If your system operates at 5 V, chipsets that provide
5-V to 3-V voltage translators are available, or you can provide
the translators on your system board. (If you use voltage trans-
lators, they must be fast enough to support your bus speed.)
Due to the processor’s high clock frequency, the package sup-
ports many copies of V
CC
and V
SS
to prevent power surges
when multiple outputs change state simultaneously. In addi-
tion, certain precautions must be taken with respect to the
AHOLD input. If the processor has a pending bus cycle when
AHOLD is negated, all of the address drivers turn on almost
Summary of Contents for AMD-K5
Page 1: ...AMD K5 Processor Technical Reference Manual TM...
Page 10: ...x AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 24: ...1 4 Overview AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 54: ...2 30 Internal Architecture AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 116: ...4 26 Performance AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 356: ...6 44 System Design AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 380: ...7 24 Test and Debug AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 396: ...A 16 AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 406: ...I 10 Index AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...